Bionic camouflage underwater acoustic communication based on sea lion sounds

In military confrontation, traditional underwater acoustic communication techniques with fixed frequency and modulation fashion are likely to result in the exposure of the submarine´s position. It is helpful for enhance the submarine´s concealment to use the sea background noise as carrier to perform communication. In this paper, a novel covert underwater communication method based on sea lion sounds is proposed. Properties of sea lion sounds are investigated firstly. According to the analysis result, sea lion click sound is used as information carrier and whistles are used as synchronization. Information is modulated on the compressed click based on the dual-orthogonal modulation method. For improving the receiving SNR, the channel equalization is performed by passive time reversal mirror technique, whereas channel estimation is done through matching pursuit method under the theory of compressed sensing. The efficiency and feasibility of the proposed method are verified by the simulation.